The present invention relates to user access systems and service provider host systems for data and service networks, particularly but not exclusively for use with the Internet/World Wide Web, and to means for managing communications of a user.
Recent years have seem a rapid increase in the amount of data available to a user via data network coupling to remote server, with cheap browser packages for home personal computer (PC) users and dedicated (and cheaper than PC) access mechanisms such as WebTV greatly increasing the number of people on-line. A number of examples of network access and server systems, whether for the Internet or on a smaller local area network (LAN), are described in the introduction to EP-A-0 732 660 (Kambayashi et al/Toshiba) which relates to a mechanism for providing a degree of personalisation in service provision.
In the system described, a number of client systems (for example home users) are enabled to access, via network, data stored by a server. Each of these users is registered with the server having provided to it certain personal details such as an e-mail address and/or telephone number and optionally a photograph. In operation, when a user is accessing a particular store or field of data held by the server, the server provides to the user a list of those other users concurrently accessing the data, perhaps providing an on-screen display of the photographs of those registered users.
As the number of devices having means to access servers, applications, other users and so forth using networks such as the Internet continues to grow, as well as the number of assets and service provider types, the greater the communications traffic loading becomes on individual servers, with users whose access systems are registered with such congested servers suffering from correspondingly poor performance.
It is therefore an object of the present invention to provide a means whereby networked communications systems can reduce loading on individual servers without adversely affecting the performance of those devices set up to establish communications via such servers.
In accordance with a first aspect of the present invention there is provided a network communications system comprising a plurality of devices interconnected for the exchange of data, the system including:
a user device including a communications subsystem operable to establish communications with selected other devices of the system;
a plurality of servers;
at least one domain master station, the or each such station being connected to monitor communications traffic loading at each of a respective group of said servers;
a redirector station coupled with said at least one domain master station and accessible by said user device, said redirector station being arranged to select an optimum server to handle communications of a user device on the basis of both the physical location relative to the user device and current communications traffic loading, and to instruct said user device to re-establish network communications via said selected server. In one embodiment, the or each redirector station may determine current communications traffic loading for a server through measurement of delays in communications therewith. Alternatively, or in addition, the or each redirector station may determine, at least partially, current communications traffic loading for a server from CPU and/or memory loading data supplied on request by the server.
Through monitoring by the redirector station for non-responsive servers (as will be described hereinafter), the user access becomes independent of nonfunctioning servers as well as generally being improved in performance through avoiding servers which are congested with traffic. The system suitably comprises a plurality of user devices and domain master stations, with each user device being registered as a client with at least two domain masters, and each such domain master including storage means maintaining a database of registered user device identification data. Since each user device could, in theory, access any server, the need to synchronise user data across all servers would be prohibitive: to avoid this, the user data is suitably just held by one (or preferably at least two) domain masters from where it is accessible by all servers within that domain.
With user data stored at two or more domain masters, each domain master database entry suitably includes identification of the at least one other domain master with which the user device is registered, with the domain masters being configured to transmit received changes to the identification data of a registered device to the or each other such domain master and to update the database on receipt of such changes. In this way, the contents of the users record (as held in two or more domain masters) are synchronised.
The system may feature a plurality of redirector stations, with the or each user device holding means for accessing at least two of said stations. In such an arrangement, the or each user device may hold said means for accessing in the form of network addresses for a first, preferred, redirector station and one or more further, back-up, redirector stations, with the or each back-up redirector station being accessed by a user device only in the event of failure to access the preferred redirector station.
Each server suitably includes a cache memory into which user device information (where provided) is loaded from the domain master for the group including that server on accessing of that server by the registered user. With such an arrangement, each server is preferably configured, on failing to access a domain master station holding identification data for a connected user device, to determine the previous server to which the said user device was connected and request the user identification data from the cache memory in that server.
Further features and advantages of the present invention will become apparent from reading of the following description of preferred embodiments of the present invention, given by way of example only and with reference to the accompanying drawings in which: